Drill.



The wall of the casing 10 is provided with' openings 35 and 36, spaced.trom each other longitudinally in said wall. At a point be tween saiddischarge openings is an intake passage or opening 37 with whichcommuniw lcatas a feed pipe 38, for furnishing com- 'pressed air. Theclutch member 28 and the stein. 29 are provided with the longitudinalopeningn 39, extending from the upper surface of the clutch memberdownwardly a sufficient distance. il. lateral opening 40 communicateswith the interior of the easing 'i0 and with the passage or opening 39.

, The parts hereinbefore described are of such construction that thepractical opera tion of my improved drill is as follows: Assuming theparts to be in the position shown in Fig. 1, air is supplied through thesupply pipe 38 and passes into the groove 17, thence through the byLpass34 to the space around the portion 18 of the piston 16 below theshoulder 42. vThe upward pressui'e of the air against the shoulder 42forces the piston upwardly. rUpward pressure is imparted on the clutchmember 28, which is thereby locked in position. lt will be understood ofcourse that the 'clutch member is normally held locked by the spring 41surrounding the stem 29 between the body 11 and the lower surface of theclutch member 28. it will therefore ap pear that during the upwardmovement of the piston 16. the effect of the' screw members 30 and 3Qwill be to rotate the piston 16. The portion 19 of the piston will slideupwardly but at the same time will rotate the sleeve vQ3, which in turnwill rotate the drill point 24e.

When the piston moves upwardly and the groove 17 clears the upper end ofthe bypass 34. the expansion of the air in the space around the member18 will continue to force the piston toward the upper limit of itsmovement although the passage of the air or other fluid through the pipe38 will be stopped duringI part of the upward movement of the piston.

When the piston has moved upwardly to the point where the upper end ofthe groove 17 registers with the lower' end of the by-pass 33, air fromthe pipe 88 will pass upwardly through said lay-pass to the space abovethe piston. At about the same time the shoulder 42 moves to positionabove the lower part of the discharge passage 36 and per- :temper theclutcn member 28 forcing the clutch member downwardly and releasing itfrom engaging with clutch member 15. The pressure of the sir starts thepiston. downwardl and. its doar-.ward movement is continus by tbeexpansion ce" the air by gravity.

@n account oi the ract that the clutch members are not in engagement,the piston i6 does not rotate during its downward movement. fit lwillthus be seen that die constant pressure oi the air troni the pipe 38causesA an intermittent, rotary movement ci the' drill point 2li, andcause en alten netting, reciprocating movement ton 16. During one strokeoi? it is rotated and during :the otne movement longitudinal only.

ln Fig. 'i have shown a modified 'torni' oit the clutch member. Formedon 'the plus 14C in the modified form of the invention is a corrugated.lower face 50. Formed on the stem 29 is a plate or clutch member 51,having its upper face corrugated. The central adjacent portions ot theclutch, members 5G and 51 .are cut away to 'torni openings 5&2 and 53.The opening '53 communicates with the passage The other parte are substantially of the same construction as shown in Fig. ."l.

Fig. 3 shows a vertical, central, sectional View, with the exceptionthat the members 5() and. 51 are shown artially in elevation to betterillustrate their construction. The operation of the parts is the same asthat already described.

My improved drill has a number of advantages, many oi which may be seenfrom the foregoing description. By the use oi? compressed air or othersuitable duid, i( am able to impart to the drill an intermittent rotarymotion by means of the continuous air pressure furnished through thesupply pipe 33. The parts are of comparatively silrlple construction,and are so assen'xbledl strelen its that hey may be readily and easilyteitenv apart for repairs or replacing worn parts.

lt will. be understood that some changes may be made in the details oit'the 'construction of my improved drill without departU ing from itsessential features and it is my intent to cover any such changes whichmay be included within the scope of my claim.

l claim as my invention:

in a device ot the class described, a holn low casing, a piston having alongitudinal opening in the upper end and adapted to reciprocatetherein, means for reciprocating said piston, a clutch membertiredwithin the upper endof the casing, a second clutch member adapted toooact with the iirst and piston Air pass-es through Sil wiege? ef suchshape as to form an air.' chamber be coast with the rie on the bei", andmeans tween said clutch members, a rife bar ixed for yieldingly holdingsaid clutch members 1 to and extending downwardy from 'the last inengagement. described clutch member into the opening Des Moines, owa,August 1l, i914.

5 in the piston, said tie bar having a, passage Y FRANK R. VVILLEAMS.

therein connecting the ail' chamber and ehe Witnesses: upper end of thecasing, a nut xed Within 5. H. MITCHELL,

he opening in the piston and adapted sbo JQSEPH C. MITCHELL.

